Photovoltaic junction boxes are generally rectangular, low-profile plastic housings that protect electrical connections against the rigorous challenges of the outdoor environment at various points within a photovoltaic installation, from individual solar energy collection panels into power collection circuits and power management equipment for delivery to a local electrical load circuit or outgoing power transmission lines. These junction boxes may contain a varying number of wiring compartments and may be provided with wiring terminals, connectors, or leads to accommodate current-carrying conductors in a secure manner to assure that reliable and reproducible connections can readily be accomplished in the field.
Photovoltaic junction boxes must therefore be manufactured to exacting tolerances to provide a durable weather-resistant housing for electrical connections that maintains its protective integrity while withstanding challenges such as impacts from objects, wind-driven rain, and exposure to extreme heat, damaging ultraviolet radiation, and fire. Therefore, polymeric materials used for the manufacture of photovoltaic junction boxes must simultaneously meet several property requirements relating to moldability, flame retardancy, heat resistance, and ductility. In addition, the polymeric materials must have good oxidation resistance to retain useful properties for an extended period of time in outdoor use.
Some poly(phenylene ether)-based resins are currently used for photovoltaic junction boxes and connectors. These compositions provide a desirable property balance of the properties described above. However, particularly when the photovoltaic junction box is constructed from potting silicone sealant as well as the poly(phenylene ether) composition, known poly(phenylene ether) compositions can provide inadequate adhesion to the potting silicone sealant. There is therefore a need for poly(phenylene ether) compositions with improved adhesion to potting silicone sealant.